It’s no secret that search engine optimization (SEO) strategies have changed. The relationship between being active in social media and its effect on your search engine rankings (AKA PageRank) has been widely illustrated from expert to expert. The solidifying factor was the introduction of Google+, the Google +1 button and Google+ Authorship.
Many knew social media network activity had an effect on that coveted first place search engine ranking, but it was Google that first showed how deep the SEO rabbit hole really went.
Via Antonino Militello